diff --git a/src/preamble.js b/src/preamble.js
index d03f77c880588..7585eaef04c2a 100644
--- a/src/preamble.js
+++ b/src/preamble.js
@@ -41,7 +41,12 @@ if (!globalThis.WebAssembly) {
 
 // Wasm globals
 
-#if SHARED_MEMORY
+#if SOURCE_PHASE_IMPORTS && MODULARIZE == 'instance'
+// In MODULARIZE=instance mode the output is itself an ES module (it is not
+// wrapped by modularize.js), so the source phase import is emitted here at
+// module scope, next to where wasmModule is used.
+import source wasmModule from './{{{ WASM_BINARY_FILE }}}';
+#elif SHARED_MEMORY
 // For sending to workers.
 var wasmModule;
 #endif // SHARED_MEMORY
diff --git a/test/codesize/test_codesize_minimal_O0.expected.js b/test/codesize/test_codesize_minimal_O0.expected.js
index d51078ecef6c7..2768cbc816e18 100644
--- a/test/codesize/test_codesize_minimal_O0.expected.js
+++ b/test/codesize/test_codesize_minimal_O0.expected.js
@@ -20,7 +20,7 @@
   // globalThis because older browsers might not have globalThis defined.
 
   // We skip the node version checking when running on Bun/Deno since the node
-  // version they report is not completely.
+  // version they report doesn't seem to be useful.
   if (typeof process !== 'undefined' && !process.versions?.bun && typeof Deno == "undefined") {
     var currentNodeVersion = process.versions?.node ? humanReadableVersionToPacked(process.versions.node) : TARGET_NOT_SUPPORTED;
     if (currentNodeVersion < 180300) {
diff --git a/test/codesize/test_unoptimized_code_size.json b/test/codesize/test_unoptimized_code_size.json
index cdd575261b0d5..ef39819ba2646 100644
--- a/test/codesize/test_unoptimized_code_size.json
+++ b/test/codesize/test_unoptimized_code_size.json
@@ -1,16 +1,16 @@
 {
-  "hello_world.js": 56114,
-  "hello_world.js.gz": 17666,
+  "hello_world.js": 56122,
+  "hello_world.js.gz": 17671,
   "hello_world.wasm": 15115,
   "hello_world.wasm.gz": 7464,
   "no_asserts.js": 25585,
   "no_asserts.js.gz": 8688,
   "no_asserts.wasm": 12229,
   "no_asserts.wasm.gz": 6004,
-  "strict.js": 53216,
-  "strict.js.gz": 16637,
+  "strict.js": 53224,
+  "strict.js.gz": 16642,
   "strict.wasm": 15115,
   "strict.wasm.gz": 7461,
-  "total": 177374,
-  "total_gz": 63920
+  "total": 177390,
+  "total_gz": 63930
 }
diff --git a/test/test_other.py b/test/test_other.py
index 6c8c26e4906d7..8edf887dee810 100644
--- a/test/test_other.py
+++ b/test/test_other.py
@@ -440,6 +440,18 @@ def test_esm_source_phase_imports(self, args):
     self.assertContained('import source wasmModule from', read_file('hello_world.mjs'))
     self.assertContained('Hello, world!', self.run_js('hello_world.mjs'))
 
+  @requires_node_25
+  @parameterized({
+    '': ([],),
+    'O3': (['-O3'],),
+  })
+  def test_esm_source_phase_imports_instance(self, args):
+    self.set_setting('SOURCE_PHASE_IMPORTS')
+    self.set_setting('MODULARIZE', 'instance')
+    self.cflags += ['-Wno-experimental'] + args
+    self.do_runf('hello_world.c', 'Hello, world!')
+    self.assertContained('import source wasmModule from', read_file(self.output_name('hello_world')))
+
   @parameterized({
     '': ([],),
     'node': (['-sENVIRONMENT=node'],),